This application is for a Mentored Research Scientist Development Award (K01) for Katherine Ornstein, PhD, an Instructor in Geriatrics and Palliative Medicine at the Icahn School of Medicine at Mount Sinai. I propose to develop expertise in five areas that will allow me to develop a line of research into the downstream effects of end of life care on family networks: 1) data linkages; (2) economic and policy issues facing older adults with serious illness and their families including knowledge of healthcare delivery and treatments at the end of life; (3) cost analysis and use of claims data; (4) analysis of complex longitudinal surveys; and (5) social network analysis. Under the guidance of my mentorship team led by Albert Siu, MD MSPH, Professor and Chairman of the Brookdale Department of Geriatrics and Palliative Medicine at Mount Sinai, I will use the skills obtained in these training areas to begin to fill outstanding gaps in our understanding of how end of life care intensity impacts families with three research projects, for which the K01 will allow me protected research time. End of life care for older patients with serious illness such as dementia commonly includes high intensity treatments which may be burdensome and costly. Our understanding of how these treatments impact patients' families' health and healthcare utilization both before and after a patient's deat is limited. Current end of life healthcare cost estimates do not consider potential downstream costs associated with the healthcare expenditures of family members who care for their seriously ill loved ones. First, I will investigate the differential impact of end of life treatmens on spousal healthcare expenditures following death of older patients with serious illness using longitudinal survey data from the HRS cohort combined with individual Medicare claims and regional data from the Dartmouth Atlas of Healthcare (Aim 1). Next, I will determine the association between healthcare treatment intensity and caregiver healthcare expenditures for patients with end-stage dementia using data from HRS and a clinical cohort of dementia patients and their caregivers (Aim 2). Finally, I will characterize the trajectory of healthcare utilization for spouses before and after patient death using Denmark population registry data (Aim 3). In addition to these research aims, my K01 award period will focus on preparation of an R01 grant proposal to link healthcare utilization of decedents to the health and healthcare of all adult family members using population registries. These projects are feasible only if I have protected time for new training and research, which K01 funding will provide.